These points are also on the negative side of the x axis, at -pi/4 and -pi/2. When we move along the x axis, notice what happens to the y value. On the left side of zero, tangent is negative. At x=-pi/4, tangent=-1.
The Independent Online. David Cameron may have called a referendum on the EU to blackmail Europe, according to Vladimir Putin. The Russian president also questioned Mr Cameronâs decision to call the vote, as it has caused a âgreat problemâ.
Russian Prime Minister Vladimir Putin claimed victory in Russia's presidential election Photo: AP. A woman helps herself to a free newspaper in a metro station in Moscow Photo: REUTERS/Sergei Karpukhin. Head of Russia's Central Election Commission Vladimir Churov Photo: REUTERS/Thomas Peter.